The present invention relates to storage area network (SAN) systems.
Storage area networks, or SANs, are networks of storage subsystems connected to servers. The goal of a SAN is to allow multiple servers of different operating systems (Unix, NT) to each “see” one large data repository. SANs provide four key benefits over direct attached storage: reduced utilization (increased bandwidth) on the Local Area Network and increased reliability, manageability, and scalability.
A current trend in SANs is storage virtualization. Storage virtualization describes the process of representing, to a user, a number of discrete physical storage devices as a single storage pool having a single set of characteristics. For example, in a storage area network connecting host computers with storage devices, the user perceives a single block of disk space with a defined reliability (e.g., 100 GB at RAID1); however, the user's host computer is configured to access the storage devices such that 100 GB at RAID1 is provided, regardless of whether the data is stored on a single RAID1 disk array or is split across multiple, separate disks.
Most of the solutions available in the marketplace today to virtualize SAN are software based. There are solutions that are host based, storage based and SAN based. For host based solution, each host computer must be aware of the storage devices connected to the storage area network because each host computer manages the storage virtualization that is presented to its users. When the storage devices connected to the storage area network are modified (such as a new device being added or an existing device being removed), each host computer must be reconfigured to accommodate the modification. Such reconfiguration involves work by network administrators and are error prone. The storage based solutions have similar issues. The SAN based solutions are better than the host and storage based solutions but lack scalability and performance.
The present invention is directed toward improvements in this and other areas.